Stereoscopic attachment for photographic cameras.



PATENTED JAN. 1, 1907.

W. SALOW, STEREOSUOIPIO ATTACHMENT FOR PHOTOGRAPHIG CAMERAS APPLICATION FILED NOV. 16. 1905.

lii/izfor Z flazieznz/ Ja/ Z0 20 UNITED STATES PATENT OFFICE.

WILHELM SALOW, OF ELBERFELD, GERMANY.

Specification of Letters Patent.

Patented Jan. 1, 1907.

Application filed November 16, 1905- Serial No. 287.645. I

To all whom it may concern/:

Be it known that I, WILHELM SALOW, philosophy student, a subject of the King of Prussia, German Emperor, residing at Elber feld, in the Kingdom of Prussia, German Em ire, have invented certain new and useful mprovements in Stereoscopic Attachments for Photographic Cameras, of which the following isa specification.

This invention relates to a device for producingstereoscopic pictures in photographic cameras and meansto provide a device of such class in a manner as hereinafter set forth which when used in connection with a photographic camera will produce two pictures consecutively in the camera, with the distance between the pictures equal to the average distance between the eyes'that is to say, they constitute stereoscopic pictures.

-Heretofor'e stereoscopic photographs have usually been taken by means of special expensive photographic apparatus the socalled stereoscopic apparatus-but by employing the stereo attachment according to thisinvention stereoscopic photographs can be taken in a perfect manner by means of an ordinary photographic camera. I

A construction of the stereo attachment according to this invention is illustrated, by way of example, in the accompanying drawings, in which- Figure 1 is a horizontal longitudinal S. tion; Fig. 2, a front elevation, and Fig. 3 shows how the attachment is connected to the object-glass of the camera.

The two rectangular equilateral prisms 1 and 2 are so placed together that their hypotenuse-surfaces a l) and 0d are parallel. The len th of the small sides a 0 or b d or 0' b is pre erably thirty-four millimeters-that is to say, a little more than half the distance between,the eyes, for the pur ose of obtaining the} desired steroscopic e ect. The two prisms 1 and 2 are arranged in a casing 3, which is dull black inside and which is provided at .the back with a socket 4 for the purpose of placing it on the objectglass of a photo aphio camera. Thetwo risms ar- 'range in the casing form a para lele iped,

as will be evident by reference to ig. 1. The front and theback surfaces of the stereo attachment constituted by the prisms 1 and 2 are uncovered for the pur ose of admitting rays of light to the object-g ass. In order to do away in this combination of prisms with chromatic phenomena due to the rays striking hypotenuse-surfaces a b and c d at a smaller angle than forty-two degrees,- Fig. 1,

and to bring the image produced exactly into the center of the sensitive plate of the pho. ographic camera, the combination of prisms is arranged slightly outside the center a: y of the socket 4 of the prismscasing 3 and at an angle a to the obj ectglass lens, Fig. 1. The size of the said shifting and of the angle of the combination of prisms relatively to the object-glass depend on the kind of glass used.

prism combination in one position and the thick dotted lines in the other position. The thin full lines and the thin dotted l nes indicate the path of rays in the two positions of the stereo attachment. By following the path of the rays it will be seen that the hy potenuse-surfaces a l) and c d of the prisms act as full reflectors, and, further, that the two surfaces in Fig. 3 represented by the lines a, c and cj correspond to two objectglasses of the well-known stereoscopic cam era. The images produced by reflection fall, however, on the same spot of the sensitive plate and not, as in the well-known stereoscopic camera, on two arranged side by side.

When using the stereo attachment, the camera is first sharply focused. Any plate, film, and instantaneous camera of any size can be used as long as it can be secured to a cured by its socket 4' to the object-glass, so that the projecting part a points, say, to the leftehand side, (see Fig. 3, full lines,) and then a photo raph is taken. Then the sensitive plate is drawn away and the attachment is turned through an angle of one hundred and eighty degrees in such manner that it projects to the right, Fig. 3 dotted. Then the second photograph is taken on a second plate. The time of exposure is of course the same as in ordinary photographs.

. Having now particularly described and ascertained the nature of my said invention and in what manner the same is to be perlIO ' pose set forth, comprising two glass prisms of rectangular equilateral shape and so arranged with respect to each other that their hypotenuse-surfaces will be in parallelism so that the rays of light will be totally reflected from the hypotenuse-surfaces, and an opa ue casing inclosing said prisms and provi' ed with means for attaching it in position.

2. A stereoscopic attachment for photographic cameras comprising a shiftable casing provided witha-sock'et forthe attachmentvofthecasing to the object glass case ofthe' camera said casing extending obliquely with respect to the obj act-glass of'thecamera, and a reflecting means substantially.par+- allelepipedal in- :contourarranged within said casing and extending, obliquely with respect to .the obj ect-glass-of the camera; said casing maintaining the said reflectingjgmeans at the same:v angle with respect to. thevlobject-glass when the said reflecting means shifted by the casing. a

3. A stereoscopic attachment for photo graphic cameras comprising a shiftablc casmg provided with a socket at one end adapted to be connected to the camera-body, and a reflecting means within said casing and arranged at an angle with respect to the said socket and extending obliquely with res set to the object-glass ofthe camera, sai reflecting means shiftable with the casing and maintained; at the same angle with respect to the object-glass when shifted by the casing.

In testimony whereof Ihavehereunto set myhand in presence oi two. subscribing witnesses.

i -WILHELM SALOW.

Witnesses: V

WOLDEMAR HAUPT; HENRY HAsPEm. 

